Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, how many whole exome sequencing tests were carried out by the NHS in order to detect rare diseases in individuals in each of the last three years; and what recent assessment she has made of their effectiveness.

The available data shows that since April 2021, 16,022 whole exome sequencing tests have been carried out to detect rare diseases. While NHS England does not hold data on the effectiveness of all exome sequencing tests, the Rapid Whole Exome Sequencing Service for acutely unwell children was launched in 2019 has provided or confirmed a diagnosis for approximately 45% of children tested via this service. The National Fetal Exome Sequencing Service launched by the National Health Service in October 2020 has provided or confirmed a diagnosis to approximately 40% of pregnant women tested via this service.